MASTER CYLINDER FOR A HYDRAULIC MOTOR VEHICLE BRAKE SYSTEM

摘要

The invention relates to a master cylinder 1 for a hydraulic motor vehicle brake system, having at least one piston 3, 4 which is arranged in a housing 2 such that it can be displaced along an axis L as a result of a brake actuation and to which is assigned a pressure chamber 5, 6, which can be connected to wheel brakes, and a replenishment chamber 7, 8, wherein in the non-actuated state, the pressure chamber 5, 6 can be connected via a compensating bore 9, 10 to a pressure medium vessel, and in the event of a brake actuation, for the purpose of obtaining a pressure build-up, said pressure chamber can be separated from said pressure medium vessel by means of a sealing sleeve 11, 12 arranged on the piston 3, 4 and the replenishment chamber 7, 8 is connected via a replenishment bore 13, 14 to the pressure medium vessel, wherein the sealing sleeve 11, 12 seals off the pressure chamber 5, 6 in the direction of the replenishment chamber 7, 8 in the event of a brake actuation, and allows additional pressure medium to be drawn from the replenishment chamber 7, 8 in the direction of the pressure chamber 5, 6 when the brake actuation is released. To provide a master cylinder of the stated type which is cheap and simple to produce, it is proposed according to the invention that the sealing sleeve 11, 12 is arranged in an encircling groove 15, 38, which is open in the radial direction, of the piston 3, 4, which groove is formed by a first and a second radially encircling projection 16, 17, 18, 19, wherein when the brake actuation is released, the drawing of additional pressure medium from the replenishment chamber 7, 8 in the direction of the pressure chamber 5, 6 takes place via the second projection 18, 19.